In the web front end all my apps are still there and I added the google account in my phone. Now how do I get the apps down to the phone?
I installed them all again. While google play knew my apps, it did not automatically install them again. So pressing install on every app brought them back.
About backup, I found that the android sdk has a backup function that backups everything, installed apps as well, next them I use that, maybe this makes reinstallation of apps unnecessary.